Damn man, that's a really bad situation. The best advice would be for you to NOT smoke in your room. Go outside and find some woods or alley or something to smoke in.

But when I was hiding pot smell from my parents, I used to take a toilet paper roll, and stuff it full of Dryer sheets (like bounty and snuggles). Then after you take a hit, blow it through the toilet paper roll. The sheets will soak up most of the smell, and make the room smell like clean clothes.

Also spray some axe body spray or something. Should cover up most of the smell. And you should do your fan idea.